Caveat: Use of the PSF Library for Detect Tools

Both celldetect and wavdetect have a parameter psftable which points to a fits file containing values of encircled energies for a wide range of off-axis angle, energy, and radii. [NB: vtpdetect uses a scale-free algorithm.]

Note however that the PSF sizes are used completely differently in the two tools: Celldetect attempts to adjust the size of the detect cell off-axis by accessing the angular radius of a circle which contains eenergy of the total counts for an unresolved source (eenergy is another parameter of both tools: encircled energy). Wavdetect however uses the PSF data only to choose the appropriate scales flux maps for estimating the source intensity; it is not used in the detection process itself.